Universality-breaking effects in leptonic Z decays.
نویسندگان
چکیده
We analyze the possibility of universality violation in diagonal leptonic decays of the Z boson, in the context of interfamily ”see-saw” models. In a minimal extension of the Standard Model with right-handed neutrino fields, we find that universality-breaking effects increase quadratically with the heavy Majorana neutrino mass and may be observed in the running LEP experiments. PACS numbers: 12.15.J, 13.38, 14.80.E ∗Address after 1, Oct. 1993, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, ENGLAND. E-mail address: [email protected]
منابع مشابه
Confronting left-right symmetric models with electroweak precision data at the Z peak.
In view of the recent and future electroweak precision data accumulated at LEP and SLC, we systematically analyze possible new physics effects that may occur in the leptonic sector within the context of SU(2)R × SU(2)L × U(1)B−L theories. It is shown that nonobservation of flavour-violating Z-boson decays, lepton universality in the decays Z → ll̄, and universality of lepton asymmetries at the Z...
متن کاملUniversality , Rare Decays and Split Fermions
We investigate the constraint on the split fermions in extra dimensions by considering the universality of W leptonic decays W → liνi, the lepton decays li → ljνiν̄j, the lepton flavor violating process li → l̄jlklh and the li → ljγ transition where li = e, μ or τ . For the Standard Model (SM) background of W → liνi, we extended the one loop quantum correction to include effects of order ml /M 2 ...
متن کاملConstraints on R–parity violating couplings from lepton universality
We analyze the one loop corrections to leptonic W and Z decays in an R– parity violating extension to the Minimal Supersymmetric Standard Model (MSSM). We find that lepton universality violation in the Z line–shape variables alone would strengthen the bounds on the magnitudes of the λ couplings, but a global fit on all data leaves the bounds virtually unchanged at |λ33k| ≤ 0.42 and |λ23k| ≤ 0.5...
متن کاملSterile neutrinos in leptonic and semileptonic decays
We address the impact of a modified Wlν coupling on a wide range of observables, such as τ leptonic and mesonic decays, leptonic decays of pseudoscalar mesons, as well as semileptonic meson decays. In particular, we concentrate on deviations from lepton flavour universality, focusing on the ratios RP = Γ(P → lν)/Γ(P → l′ν), with P = K,π,D,Ds, R(D) = Γ(B + → Dτ+ν)/Γ(B+ → Dl+ν), Rτ = Γ(τ → μνν)/Γ...
متن کاملProspects of Probing New Physics in Bottomonium Decays and Spectroscopy *
A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breaking in Upsilon leptonic decays. Moreover, mixing between such a pseu-doscalar Higgs boson and η b states might shift their mass levels, thereby modifying the values of the M Υ(nS) − M η b (nS) hyperfine splittings predicted in the standard model. Besides, η b resonances could be broader than ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 71 17 شماره
صفحات -
تاریخ انتشار 1993